Corrugated-paper tube



G. H. BARTLETT.

CORRUGATED PAPER TUBE.

APPLICATION FILED FEB. 14. 191B.

Patented Oct. 21, 1919.

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Specification of Letters Patent.

TED STATES PATENT OFFTCE. ononen n. nanrnnrnor sAn rnmrcrsco, cumrom'a,nssrenon r zunrroimn or SAN FRANCISCO, cnmromvm, A CORPORATION orCORRUGATED-PAPER Patented @ct. 21,1919.

Application filed February M, 19-18. Serial No. 217,062.

' tion.

This inventionrelates to a paper tube and the process of making same.

It is the principal object of this invention v to provide a paper tubewhich may be rapidly manufactured and which is so formed as to possessconsiderable strength as well as to provide an interior lining which iwill protect fragile objects inclosed therein.

The. present invention contemplates the use of flat cardboardsheetswrapped helically upon a paper tube forming machine of commonconstruction and which are combined in the course of manufacture withlayers of helically arranged sheets of corrugated cardboard.

Certain forms into which the tubes are made and an embodiment of amachine for producing such tubes are illustrated by way or example inthe accompanying drawings, in which Figure 1 is a view disclosing alength of tube formed according to the spirit or the present -inventionand with a portion of its outer wall broken away toindicate the joint Iin the wall layer therebeneath.

Fig. 2 is a View in transverse'section, as seen on the line 22 of Fig.1, illustrating the correlation of the outer solid-wall and the innercorrugated wall combined therewith.

- Fig. 3 is a'view in transverse section illustrating the tubing as.crushed to conserve space in'shipping.

Fig.4 is a fragmentary view illustrating the arrangement of the outerand inner thicknesses of the tube wall and themanner in which theirjointsare disposed.

' V Fig. 5 is a view in diagram disclosing one form of tube wrappingmachine upon which the tubes may be made.- i I Fig. 6 is a-view intransversesectiomdisclosing a second form o fjtube having-an inner andouter thickness of cardboard-and an interposed layer of corrugatedmaterial.

.' Referring morepartiou arly to the 'drawings,'10 indicatesthecylindrical mandrel mandrel and are used to wrap strips of card-' boardlt'and thereon with the side edges of the coil in abutting relation.

As illustrated in Fi 5, the cardboard it is smooth and flat while thecardboard I5 is corrugated. As arranged, the corrugated cardboard willbe wrapped directly around the mandrel and the, smooth cardboard wrappedthereover;'1 the joints of the con- I volutions of each cardboardoccurring intermediate the width of the other cardboard, as particularlyshown in Fig. 4. While the belts are driven in the direction of arrowsa, as shown in Fig. 5, the two-ply tube will be. formed and the twolayers of cardboard will be helically arranged. The layers are arrangedin overlapping relation, the side edges of the smooth layer beinglocated at the median plane of the corrugated layer and the corrugatedlayer having its side edges located at the median planes of the smoothlayer.

As the wrapping continues the tube will be forced along themandrelinthedirection of arrow 72, it being understood that a suitable adhesivematerial has been applied 7 to the adjacent faces of thetwo cardboardlayers so that theywill adhere to form atube having the cross sectionindicamd in Fig. 2.

A tube or the character shown in'Fig. 2'

' will have a helically wrapped outer wallof smooth cardboard and ahelically wrapped inner wall of corrugated cardboard. It Wlll be readilyrecognized that these two walls so arranged willuhave greater-strengththan twosimilar walls of smooth cardboard, due to the corrugations ofthe board and their helical arrangement and that a desirable. cushionwill be formed to protect fragile objects packedwithin the tube. Inorder to conserve space in shipping-the empty tubes a pair of crushingrollers 16 and 17 is spaced a jacent to the outer end of the mandrel l0and equidistant from the longitndinal axis thereof. lln this manner theywill provide a throat through which the tube will be forced. This willcause the rollers to crush the tube, as shown in Fi 3, after which itmay be cut in lengths by t e revoluble cutting member 18.

It will be readily recognized that paper tubing designed for differentuses may be made by this machine and its strength readily determined.Fig. 6 discloses one other form of the tube which is provided with anouter smooth cardboard layer 19, a smooth inner layer 20 and anintermediate layer of cardboard 21, all of which are helically wrappedand are treated with an adhesive material to form a unitary wallstructure. This form of tube will thus have smooth inner and outer wallsand an intermediate stifi'ening and buffer wall. It is evident thatother modifications of the invention could be readily produced asoccasion demands.

It will thus be seen that wheli'paper tubes are formed according to thespirit of the present invention their walls will be uniform in thicknessand the smooth layers of the walls perfectly flat without creases andbreaks as commonly occur when combining flat cardboard and corrugatedpaper to form circular containers. It will further be noted that due tothe fact that the corrugations extend helically the strength of the tubewill be materially increased without adding to its weight, and thusstrong protective tubes may be made of paper in a rapid and inexpensivemanner not possible when made as commonly constructed.

While I have shown the preferred form of my invention as now known tome, it will be understood that various changes inthe combination,construction and arrangement of parts may be made without departing fromthe spirit of the invent-ion as disclosed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is- 1. A paper tube comprising alternate layers of smoothand corrugated paper helically wrapped in overlapped relation to eachother, each layer having the side edges of its convolutions in abuttingrelation.

2 A paper tube comprising an outer layer of smooth cardboard wrappedhelically, and an inner layer of corrugated cardboard wrapped helicallyin overlapped relation with respect to the outer layer and glued to thesaid outer layer to form a composite wall, the side edges of theconvolutions of each layer being in abutting relation.

3. A cardboard tube comprising layers of flat cardboard and layers ofcorrugated cardboard arranged helically and glued in overlapped relationto each other with the side edges of one of the layers at substantiallythe median line of the other layer.

4. A method of forming a cardboard tube, consisting in simultaneouslywrapping layers of smooth and corrugated cardboard in overlappedrelation around a forming mandrel with the side edges of one layeratsubstantially the median line of the other layer.

and applying an adhesive material to their adjacent sides whereby acomposite tube will be formed.

5. A method of forming corrugated cardboard tubes consisting insimultaneously wrapping layers of flat and corrugated cardboard upon acylindrical mandrel and in superimposed overlapping relation to eachother, afpplying an adhesive to the adjacent faces 0 the layers, andthereafter passing the tube through a pair of crushing rolls after whichit is severed into lengths.

6. A paper tube comprising layers of flat and corrugated cardboardhelically wrapped in overlapping relation with the side edges of thecorrugated layer substantially at the median line of the smooth layerand with the cofiugations extending spirally around the tu In testimonywhereof I have hereunto set my hand in the presence of two subscribingwitnesses.

-GEORGE H- BARTLETT. Witnesses:

C. S. RUTHERFORD, W. S. Rms.

